Defer capital, defensibly.
BRL 25.1 M of capital deferred at 1% exposure and at least BRL 78.7 M at 5%, for BRL 0.7-1.5 M of DLR cost.
How a Brazilian DSO uncovered the capacity and the risk, hidden in the static ratings of its sub-transmission lines.
A fixed rating wastes capacity and hides risk at the same time.
17 of 23Lines where operating on DLR defers the planned reinforcement
BRL 78.7 Mof capital deferred by adding DLR to the top nine lines, at a cost of just BRL 1.5 M.
262 hOf measured load above the real capacity, unseen by the static rating
The challenge.
Reinforcements were planned on lines nearing their static limits. Could DLR defer them safely?
The DSO is one of Brazil’s largest private electricity groups, with distribution concessions in several states. Its distribution companies run 69 kV and 138 kV sub-transmission lines that carry regional load over long, often radial routes, in climates that range from the Amazon to the semi-arid Northeast and the Southeast.
The Brazilian DSO’s Business Plan schedules reinforcement works wherever the projected peak approaches the static rating, with works planned from 2027 to 2034. Before committing that capital, the group wanted an independent, line-by-line view of how much thermal capacity its conductors really have, hour by hour, and of how much risk its fixed ratings already carry.
Covering seven distribution companies at once called for a sensor-less study: tower coordinates, plan-and-profile drawings and conductor data, confronted with the utility’s own load measurements and demand projection.
How much capacity do our lines really have, how often is the fixed rating unsafe, and which planned works can DLR defer, and for how long?
How Enline delivered.
Three years of hourly ratings for every span, confronted with measured load and the Business Plan.
Enline’s GridSight® platform reconstructed hourly weather at every structure and computed the IEEE 738 rating of each of the 3,543 spans for 26,304 hours, over 90 million span-hours; each hour, the line is limited by its weakest span. The ratings were then confronted with measured current and with the DSO’s demand projection to find when each limit is reached and what DLR is worth.
Hourly DLR per span and limiting-span ranking
Firm static rating with a declared risk level
Conductor temperature and sag at the DLR, span by span
Reinforcement date, deferral and capital deferred per line
The Enline DLR value proposition.
Capacity that already exists in the asset, made visible, auditable and usable.
See the hidden risk.
The declared rating exceeds real capacity in 3-99% of hours; load already went past it for 262 hours.
Safe by construction.
At the hourly DLR, no span of the 23 lines exceeds its design temperature: design sag and clearances hold.
No hardware to start.
Run from drawings and weather models; sensors then go only to the limiting spans, to validate and operate.
Across the 23 lines with reports, the median hourly rating is 4% to 71% above a conservative static rating, yet below it in 2% to 36% of hours: one fixed number wastes capacity and hides risk.
One week, hour by hour, on a 69 kV line · 8-14 Sep 2025, local time · grey columns: 6 am to 6 pm
- Hourly dynamic rating (DLR)
- Declared static rating · 350 A
- Measured load
- Unused capacity
- Hidden risk
Where project values are known (nine lines, BRL 506 M of works), DLR defers the work on four lines at 1% exposure and six at 5%. In later batches, still without project values, 11 of 14 lines defer at 5%.
Deferral of the planned work and capital deferred (present value)
- LT02 · plan 20291% exposure tolerance: 1.1 y · BRL 4.3 M5% exposure tolerance: 6.7 y · BRL 21.0 M
- LT07 · plan 20321% exposure tolerance: 2.6 y · BRL 10.6 M5% exposure tolerance: 5.7 y · BRL 20.3 M
- LT04 · plan 20321% exposure tolerance: 2.7 y · BRL 9.8 M5% exposure tolerance: ≥ 6.0 y · BRL 19.2 M
- LT01 · plan 20291% exposure tolerance: none5% exposure tolerance: 2.6 y · BRL 12.6 M
- LT08 · plan 20281% exposure tolerance: 0.7 y · BRL 0.4 M5% exposure tolerance: 9.0 y · BRL 4.3 M
- LT06 · plan 20271% exposure tolerance: none5% exposure tolerance: 0.3 y · BRL 1.4 M
- LT03 · plan 2032no deferral: the dynamic limit is reached first
- LT05 · plan 2027no deferral: the dynamic limit is reached first
- LT09 · plan 2034no deferral: the dynamic limit is reached first
years of deferral
A fixed rating wastes capacity and hides risk at the same time.
DLR defers the planned work on 17 of 23 lines, with the risk declared in numbers.
At the hourly DLR, no span exceeds its design temperature.
The weak span moves: 11 to 326 different spans set the rating, depending on the line.
Decide · declared risk of the firm rating, exposure tolerance, and Business Plan dates and project values.
Check the network · power flow, contingencies, protection and terminal equipment must take the higher current.
Verify in the field · sag, clearances and vegetation on the limiting spans; weather checked with targeted sensors.
Operate · real-time and day-ahead DLR in the control centre, with the firm static rating as fallback.
Pilot, then scale · start where the deferral is largest, update the study yearly, extend to the remaining lines.